Computer users often work in teams. It can be useful for the teams to be able to share calendar information. For example, the users in teams often provide user input to send other team members calendar item requests, such as meeting requests that can be accepted or declined, or possibly tentatively accepted. Within computer systems such calendar item requests can be considered to be sent from one user's user profile to the other user's user profile, where the user profiles are data structures stored within computer systems. For example, such a calendar item request may be sent from one computing machine that is logged into a system or application with one user profile to one or more other computing machines that are logged into a system or application with one or more other user profiles. As another example, a user profile for one team member may share a calendar (such as a personal calendar or a group calendar) with one or more other user profiles for other team members, providing those other user profile(s) with access to the calendar.